Method for preparing norbornene and substituted derivatives of norbornene

ABSTRACT

Disclosed is a method for the preparation of norbornene and substituted norbornene compounds via a Diels-Alder reaction, in which a cyclic diene is reacted with an olefinic compound in order to prepare a norbornene compound. According to the invention a cyclic diene is gradually added to react with an olefinic compound, in order to keep the concentration of the cyclic diene in the reaction mixture as low as possible during the reaction. It is possible to obtain a very pure product, high yield, short reaction time and high concentrations of the exo diastereomer with the method of the invention.

BACKGROUND OF THE INVENTION

The present invention relates to a method for preparing norbornene andsubstituted derivatives of norbornene via the Diels-Alder reaction.

The described method comprises reacting a cyclic diene with an olefiniccompound to yield norbornene or a substituted derivative of norbornene.

The present invention also relates to a polymer prepared by polymerizinga monomer prepared by the method of the invention in the presence of acatalyst and another monomer.

Norbornene and substituted norbornene compounds are used for thepreparation of such compounds as cycloolefine-copolymers (COC). Thesecopolymers may be prepared, for example, by introducing a norbornenederivative in a metathesis-ring-opening polymerization reaction orreacting norbornene with ethene or an other alpha-olefine in thepresence of a vanadine based Ziegler-Natta catalyst or a metallocenecatalyst.

It is essential in all of these polymerization reactions that the cyclicmonomer is pure. Especially polyunsaturated impurities (such as thetrimer or dimer of cyclopentadiene) are adverse, because they causecross-linking in polymers. Other polycyclic impurities (such astetracyclododecene compounds) may also have adverse effects, becausethey cause polymer chains to be of greater rigidity than norbornene andsubstituted norbornene compounds, thereby causing the properties of thepolymers to be prepared to become different from those achieved whenpure products are used for polymerization. Furthermore, it should bepointed out that the diastereomers (exo and endo forms, respectively) ofnorbornene compounds have a different effect on polymer compounds; theexo form yields more rigid polymers than the endo form. From the pointof view of further use of the monomer, the product should contain asmuch as possible of the desired diastereomer. Usually, one attempts toachieve as high as possible a concentration of the exo diastereomer.

Because mixtures of cycloolefin compounds are difficult to purify bydistillation, it is preferable to synthesize them under conditions, inwhich the desired norbornene or substituted cylcoolefin compound (theendo or exo diastereomer of substituted norbornene or the correspondingtetracyclododecene compound) are in as pure a form as possible.

Among the substituted norbornene derivatives, e.g. phenylnorbornene(5-phenyl-bicyclo-[2.2.1]-hept-2-ene) and indanylnorbornene(1,4-methano-1,9a,4,4a-tetrahydrofluorene) are known organic compounds.They have been prepared in a batch process by using a solvent andstarting compounds in equimolar ratios. This requires a very longreaction time if a high yield and a pure product are desired. Elevationof the reaction temperature can be used to shorten the reaction time,but at the same time the product yielded turns out to be very impure(the reaction mixture contains large amounts of the trimer andtetracyclododecene compounds). On the other hand, maintaining a lowtemperature and extending the reaction time causes the undesired endoform to become the predominating diastereomer.

Some solutions to these problems have been suggested in the known art.Nippon Zeon has performed the synthesis of phenylnorbornene by using alarge excess of styrene as the solvent (EP-A2-0 345 674) and MitsuiSekka has developed a method for the isomerisation of the endodiastereomer into the exo diastereomer (EP-A1-0 499 226). It is notpossible to use these methods either for the preparation of pureproducts with high yields.

DE Published Patent Application No. 2 161 215 discloses a process forpreparing 5-vinylnorbornene-2. According to this known processcyclopentadiene is slowly added to a mixture of butadien anddi-tert-butyl-p-cresol. The reaction is interrupted after 60 minutes,when 20% of the cyclopentadiene has reacted. The yield ofvinylnorbornene is only 71.6% and the reaction mixture obtained israther impure containing a mixture of cyclopentadien, dicyclopentadien,butadiene, 5-vinylnorbornene-2 bicyclonoadiene, vinylcyclohexene andresidues with higher boiling points.

The object of the present invention is to overcome the shortcomings ofknown techniques and to provide an entirely new method for thepreparation of norbornene and substituted norbornene derivatives.

The invention is based on the idea of synthesizing norbornene compoundsvia a Diels-Alder reaction while maintaining a low or relatively lowconcentration of the cyclic diene. According to the invention, this isachieved by introducing a cyclic diene into the reaction with anolefinic compound gradually during the reaction to keep theconcentration of the cyclic diene low during the reaction. The reactionis continued until essentially all (at least 80%, preferably at least95% and in particular at least 99%) of the calculated amount of cyclicdiene has reacted.

The norbornene or substituted norbornene compounds obtained can be usedfor preparing polymers.

More specifically, in the present method, the cyclic diene is addedgradually during the reaction.

The polymer according to the present invention is prepared bypolymerizing a monomer prepared by the above described synthesis in thepresence of a catalyst alone or in the presence of another monomer.

The present invention provides considerable advantages. The describedmethod of the invention enables one to achieve a very pure product, highyield, short reaction time and, if desired, high concentrations of theexo diastereomer. Thus, after the reaction, the concentration ofunreacted cyclic diene reactant in the reaction mixture is typicallyless than 3.0 wt-% and the concentration of the undesired trimer of thediene less than about 0.10 wt-%. It is even possible to achieve reactionmixtures that contain practically no residues of unreacted diene and nodetectable amounts of trimer.

THE INVENTION

Within the scope of the present invention, the statement that a cyclicdiene is introduced into the reaction “gradually”, is understood in sucha way that at least a part of the diene is reacted with an olefiniccompound only after the reaction has already started. According to theinvention, the cyclic diene, such as cyclopentadiene, formed in orbefore the reactor, is diluted in the reaction mixture and/or reacts sorapidly that dimerisation, trimerization, tetramerization and the likedo not occur.

The present invention can be performed in a number of ways in accordancewith its basic principles. Therefore, the preparation process may be asemi-batch or a continuous process, in which a cyclic diene is added asit is consumed in the reaction with an olefinic compound. A continuousprocess can be performed in, for example, an autoclave intended forcontinuous operation, a tube or loop reactor or in a cascade comprisingany of these reactors. In a continuous process a cyclic diene is mostpreferably added evenly during the reaction, in order to provide asuitably low diene concentration. The addition of diene can, however, beincreased or decreased (or even cut off temporarily) during the processto vary the diene concentration.

In a semi-batch process a diene is added as a function of time. Inpractice, a portion of the diene is first fed to the reactor togetherwith an olefinic compound to form a reaction mixture, whereafter therest of the diene is introduced into the reactor in one or more aliquotsor as a continuous stream after the reaction has progressed for sometime. Typically, the reaction is allowed to proceed for some tens ofminutes before more diene is added into the reactor. This time issufficient to allow about 1-90%, preferably about 5-80% and mostpreferably about 10-70%, of the diene to react to form norbornene or anorbornene derivative. The amount of added diene is typically equimolarwith respect to the olefinic compound. In this case, the total amount ofdiene added to the reaction mixture at the beginning is most suitablyless than equimolar with respect to the olefinic compound. According toone preferable alternative the molar ratio of the olefine and the dieneis 51:49-99:1, preferably 55:45-90:10 and most preferably about80:20-60:40, at the beginning of the reaction.

The reaction can be enhanced, in addition to the addition of diene, bycontrolling the reaction temperature and by selecting a suitablereaction system, in order to yield an end product of preferablecomposition. As shown in the Examples, by suitable selection of theratio of the reagents and/or the reaction temperature, the yield andpurity of the norbornene compound or the yield of the exo diastereomerof the norbornene compound or the yield of tetracyclododene can bemaximized. Similarly, the ratio of the reagents, the reactiontemperature and/or the reactor system can be selected in such a way thatthe time of synthesis is minimized and the rate of production ismaximized.

The temperature can be controlled in alternative ways, such as forming atemperature ramp in a semi-batch process and arranging a temperatureprofile in a continuous process. In both of these cases the reactiontemperature is typically 150-300° C., preferably about 160-250° C. andmost preferably about 170-220° C. Less impurities are formed at lowertemperatures but the time required for the synthesis is longer. Thesynthesis time can be shortened by elevating the temperature at thestage when the concentration of the cyclic diene is low, to obtain asmall amount of impurities. For this reason, it is advantageous to use alow reaction temperature during the addition of the cyclic diene,whereafter the temperature is raised as the cyclic diene is used up. Inthis mode of operation, several successive temperature ramps may lieused in a semi-batch process, and accordingly, several successivetemperature profiles may be used in a continuous process. The use ofhigh temperatures with a low concentration of the cyclic diene makes itpossible to use long synthesis times and to obtain more of the exodiastereomer of the monomer (for example, phenylnorbornene orindanylnorbornene) or more multicyclic monomers (for example, phenyltetracyclododecene or benzofluorene), and yet very little of the harmfultricyclopentadiene.

The synthesis time can also be used to control the quality of the endproduct. Thus, when one wishes to maximize the yield of the monomer(such as phenylnorbornene or indanylnorbornene), the length of timerequired for synthesis is of the order of about 2 h, but when one wishesto maximize the amount of the exo diastereomer of the monomer or theamount of multicyclic monomer (such as phenyl tetracyclododecene orbenzofluorene), the synthesis time is of the order of about 5 h.

In addition to the diene compound also the olefinic compounds, inhibitoror some other chemical compound to be introduced into the reactionmixture can be added as a function of time or into various parts of thereactor system in a manner described herein above. The solvent, olefiniccomponent or some undesirable product component (especially, dimers,trimers and tetramers of cyclopentadiene) can be recycled and possiblycracked to improve conversion.

By the present invention it is possible to obtain reaction mixturescontaining more than 80 wt-%, in particular over 83 wt-%, norbornene orits substituted derivatives and less than 3.0 wt-%, in particular lessthan 2.0 wt-%, of the cyclic diene. If desired, the proportion of theexo isomer can be increased to more than 10%, in particular more than15% of the norbornene product. As example 7 shows, it is even possibleto raise the proportion of the exo isomer to over 50%.

The amount of the undesired trimer can be reduced to less than 0.10wt-%, in particular to less than 0.05 wt-% of the reaction mixture afterthe reaction.

The invention can be used to prepare norbornene and its substitutedderivatives. When norbornene is prepared ethene is used as the olefinicreagent and dicyclopentadiene or cyclopentadiene is used as the cyclicdiene. Most suitably dicyclopentadiene is cracked immediately before thereaction to form cyclopentadiene, for example, by feeding the reagentinto the reaction mixture through a pipe with heated mantle.

When substituted norbornene derivatives are prepared, the suitableolefinic compounds include, for example, styrene, indene, alpha-olefines(such as 1-propene or 1-butene), cyclic olefines (such as cyclopenteneor cyclohexene), linear dienes (especially 1,2-butadiene), acrylic acidand methacrylic acid and esters thereof (for example, methylacrylate),and unsaturated silanes (for example, vinyltrimethoxysilane) and thesame cyclic dienes as described above.

The olefinic compounds described above, especially styrene and indene,act as the reaction medium at the same time, or in other words as thesolvent for the cyclic diene. The cyclic diene also functions as aninhibitor (it prevents polymerization of the olefinic compound).

In a preferred embodiment, the diene introduced is dicyclopentadiene andit is added in such a way that it is cracked into cyclopentadieneimmediately before the point of addition. In this case, it is mostsuitable to use a separate inhibitor (for example, 4-t-butylcatechol).

The purified or unpurified product that is prepared according to themethod of this invention can be used to produce polymers by performingpolymerization reactions of the monomer, in the presence of a metathesiscatalyst, Ziegler-Natta catalyst, metallocene catalyst or the like,alone or together with an olefine or some suitable monomer. Thus,copolymers and terpolymers of the COC type can be prepared fromphenylnorbornene by polymerizing the compound with olefines, especiallywith ethene, in the presence of metallocene catalysts. CrosslinkedRIM-polymers, elastomers and COC polymers can be obtained fromphenylnorbornene with metathesis catalysts. Corresponding products canbe obtained from indanylnorbornene and norbornene. Ethylidenenorborneneis suitable for the preparation of EPDM elastomers. Methylacrylatesubstituted norbornene can be used to prepare the COC type polymers(arton) of Japan Synthetic Rubber in a ring-opening polymerization inthe presence of metathesis catalysts. Trimethoxysilyl derivatives aresuitable for the preparation of silane crosslinked EPDM elastomers.

The following examples are given to clarify the invention. Although asemi-batch process (where a cyclic diene is added at the beginning andonce later on) is used for the sake of simplicity in the followingillustrative examples, similar conditions (combination of cyclicdiene/olefinic compound and temperature) can be achieved in acontinuously operating process (single autoclave, tube or loop or anycombination thereof in a cascade). Consequently, the examples areintended to be illustrative only and in no way restrictive of theinvention.

In the following examples, the moment of starting the experiment hasbeen defined as the moment at which heating of the reaction mixture iscommenced.

EXAMPLE 1

(Semi-Batch)

Styrene and dicyclopentadiene (DCPD) of at least 95% purity were weighedinto a reactor, in amounts corresponding to a molar ratio 76:24. 10 000ppm of 97% pure 4-tert-butylcatechol were used to preventoligomerisation reactions of the starting materials. Oxygen was removedfrom the reaction mixture prior to commencing the reaction by allowingnitrogen gas to pass through the mixture. Thereafter, the reactionmixture was heated to 180° C. and allowed to react for 4 hours, afterwhich it was cooled to 30° C. 40 minutes after the start of theexperiment pumping of DCPD into the reactor was commenced at a rate of0.850 ml/min for 20 minutes. After the pumping had stopped, the molarratio of the starting materials was 65:35. The composition of the oily,light yellowish reaction mixture is presented at various times aftercommencing the experiment in Table I.

TABLE I Composition of the oily reaction product expressed as masspercentage at various times after commencing the experiment Time/min 100130 160 190 240 270 Cyclopentadiene — — — — — — Styrene 13.89 10.05 9.689.02 10.03 3.12 Dicyclopentadiene 12.13 8.14 6.01 4.51 2.75 0.32phenylnorbornene 73.98 81.56 83.22 84.33 83.82 88.49 Tricyclopentadiene— — — — — — Phenyltetracyclo- — 0.25 1.09 2.15 3.40 7.90 dodecenePhenyltetracyclo- — — — — — 0.16 dodecene isomer

Example 1 shows that by using the present method the fraction ofphenylnorbornene in the product mixture is as high as 88.5% at its best,and that formation of adverse tricyclopentadiene is not detected at all.Tetracyclododecene formation begins only after 130 minutes after thestart of the experiment and the formation of its isomer after 270minutes. From the point of view of performing the steps for separation,the best moment to stop the reaction is at 120 minutes.

EXAMPLE 2

(Semi-Batch)

The same procedure as in Example 1 was carried out except that thepumping rate of DCPD was 0.900 ml/min and the pumping time 30 minutes.After the completion of pumping the molar ratio of the startingmaterials was 60:40. The composition of the oily, light yellowishreaction mixture is presented at various times after commencing theexperiment in Table II.

TABLE II Composition of the oily reaction product expressed as masspercentage at various times after commencing the experiment Time/min 100130 160 190 240 270 Cyclopentadiene — — — — — — Styrene 10.06 6.19 5.445.12 4.17 1.17 Dicyclopentadiene 18.31 14.64 12.65 11.33 7.60 2.80Phenylnorbornene 71.64 78.65 80.29 80.61 82.32 85.99 Tricyclopentadiene— — — — 0.09 0.28 Phenyltetracyclo- — 0.52 1.62 2.93 5.82 9.55 dodecenePhenyltetracyclo- — — — — — 0.21 dodecene isomer

Example 2 shows that in this procedure the addition of DCPD was a littletoo excessive. This shows up as formation of adverse tricyclopentadieneat the end of the experiment. The fraction of tetracyclododecene is alsoslightly larger in this case.

EXAMPLE 3

(Semi-Batch)

The same procedure as in Example 1 was carried out except that thereaction mixture was heated to 200° C. and the pumping of DCPD wascommenced 20 minutes after the start of the experiment. The compositionof the oily, light yellowish reaction mixture is presented at varioustimes after commencing the experiment in Table III.

TABLE III Composition of the oily reaction product expressed as masspercentage at various times after commencing the experiment Time/min 4060 80 100 130 160 Cyclopentadiene 0.17 0.17 — — — — Styrene 27.33 15.328.02 6.54 9.16 12.86 Dicyclopentadiene 7.87 6.72 1.09 0.12 — —Phenylnorbornene 64.74 77.28 86.01 86.39 78.21 71.26 Tricyclopentadiene— — — — — — Phenyltetracyclo- — 0.51 4.83 6.95 11.30 13.60 dodecenePhenyltetracyclo- — — 0.04 0.10 1.33 2.28 dodecene isomer

Example 3 shows that with the present method formation of the product isconsiderably more rapid. The fraction of phenylnorbornene in the productmixture is 86.4% at its best, and in addition to this, the formation ofadverse tricyclopentadiene is not detected at all. However,tetracyclododecene begins to form already 60 minutes after the start ofthe experiment, and an isomer of this 80 minutes after the start. Theproduct mixture remained fluid throughout the experiment, indicatingthat polystyrene was not formed to any adversely large amount during thereaction.

EXAMPLE 4

(Reference, Batch Process)

Styrene and dicyclopentadiene (DCPD), the purity of which was at least95%, were weighed into a reactor in an amount corresponding to a molarratio of 66:34. 10 000 ppm of 97% 4-tert-butylcatechol was used as aninhibitor to prevent oligomerization reactions of the startingmaterials. Before the reaction oxygen was removed from the reactionmixture by allowing nitrogen gas to pass through it. Thereafter, thereaction mixture was heated to 200° C. and allowed to react for 4 hours,after which it was cooled down to 30° C. The composition of the oily,light yellowish reaction mixture is presented at various times aftercommencing the experiment in Table IV.

TABLE IV Composition of the oily reaction product expressed as masspercentage at various times after commencing the experiment Time/min 2030 40 60 80 100 Cyclopentadiene 1.85 0.90 0.93 0.14 — — Styrene 48.7729.77 15.62 11.28 11.85 12.15 Dicyclopentadiene 27.70 15.17 5.76 1.910.65 0.19 Phenylnorbornene 21.68 53.90 76.47 80.53 75.60 71.12Tricyclopentadiene — — — 0.22 0.07 0.10 Phenyltetracyclo- — 0.26 1.225.57 10.26 13.73 dodecene Phenyltetracyclo- — — — 0.35 1.57 2.71dodecene isomer

Example 4 shows that with the reference method the fraction ofphenylnorbornene in the product mixture is only 80.5% at its best, andthe formation of adverse tricyclopentadiene begins to take place invarying amounts already after 60 minutes after the start of theexperiment. Tetracyclododecene begins to form already 30 minutes afterthe start of the experiment and an isomer of this 60 minutes after thestart. Additionally, as the experiment progresses the viscosity of theproduct mixture begins to increase, which results from the formation ofpolystyrene.

EXAMPLE 5

(Reference, Batch Process)

Styrene and dicyclopentadiene (DCPD), the purity of which was at least95%, were weighed into a reactor in an amount corresponding to a molarratio of 50:50. 10 000 ppm of 97% 4-tert-butylcatechol was used as aninhibitor to prevent oligomerisation reactions of the startingmaterials. Before the reaction oxygen was removed from the reactionmixture by allowing nitrogen gas to pass through it. Thereafter, thereaction mixture was heated to 170° C. and allowed to react for 130minutes, after which it was cooled down to 30° C. The composition of theoily, light yellowish reaction mixture is presented at various timesafter commencing the experiment in Table V.

TABLE V Composition of the oily reaction product expressed as masspercentage at various times after commencing the experiment Time/min 1520 30 40 60 80 100 130 160 Cyclopentadiene 8.16 1.03 0.30 0.13 0.04 — —— — Styrene 65.49 60.42 53.14 45.13 38.91 30.99 23.00 17.59 16.26Dicyclopentadiene 19.80 25.54 23.70 21.80 17.71 13.36 9.65 6.61 5.76Phenylnorbornene 6.54 13.01 22.87 29.94 43.34 55.65 67.35 75.80 77.98Tricyclopentadiene — — — — — — — — — Phenyltetracyclo- — — — — — — — — —dodecene Phenyltetracyclo- — — — — — — — — — dodecene isomer

Example 5 shows that with the batch method, in which cyclopentadiene andthe olefinic compound are added in equimolar amounts at the beginning ofthe reaction, yields a rather impure reaction mixture that containsconsiderably large amounts of the olefinic starting material anddicyclopentadiene.

EXAMPLE 6

(Semi-Batch)

Indene and dicyclopentadiene (DCPD), the purity of which was at least90%, were weighed into a reactor in amounts corresponding to a molarratio of 69:31. 10 000 ppm of 97% 4-tert-butylcatechol was used as aninhibitor to prevent oligomerisation reactions of the startingmaterials. Before the reaction oxygen was removed from the reactionmixture by allowing nitrogen gas to pass through it. Thereafter, thereaction mixture was heated to 180° C. and allowed to react for 4 hours,after which it was cooled down to 30° C. 40 minutes after the start ofthe experiment DCPD was pumped into the reactor at a rate of 0.500ml/min for 10 minutes. When the pumping was stopped the molar ratio ofthe starting materials was 65:35. The composition of the oily, darkyellowish reaction mixture is presented at various times aftercommencing the experiment in Table VI.

TABLE VI Composition of the oily reaction product expressed as masspercentage at various times after commencing the experiment Time/min 100130 160 190 240 270 Cyclopentadiene 0.06 — — — — — Indene 32.34 28.4319.23 24.55 26.71 25.01 Dicyclopentadiene 6.02 3.19 1.47 0.03 — — Endoindanyl- 53.58 58.52 67.92 61.88 58.53 57.60 norbornene Exo indanyl-8.00 9.84 10.17 12.63 12.89 14.48 norbornene Tricyclopentadiene — — 0.22— — — Benzofluorene — 0.03 1.00 0.93 1.86 2.91 Benzofluorene isomer — —— — — —

Example 6 shows that with this method the fraction of indanylnorbornenesin the product mixture is 78.1% at 160 minutes after the experimentstarted. Although the yield remains modest, it is more important fromthe point of view of the use of the product that the adverse formationof tricyclopentadiene is not detected to any significant degree.Benzofluorene begins to form only at 130 minutes after the start of theexperiment. For separation purposes, the most preferable moment to stopthe reaction would be at 120 minutes.

EXAMPLE 7

(Semi-Batch)

The same procedure as in Example 6 was carried out except that thereaction mixture was heated to 200° C. and pumping of DCPD was commencedat 20 minutes after the start of the experiment. The composition of theoily, dark yellowish reaction mixture is presented at various timesafter commencing the experiment in Table VII.

TABLE VII Composition of the oily reaction product expressed as masspercentage at various times after commencing the experiment Time/min 4060 80 100 130 160 Cyclopentadiene 0.79 0.02 — — — — Indene 40.41 36.6733.46 36.02 31.71 47.30 Dicyclopentadiene 5.50 0.87 0.01 — — — Endoindanyl- 44.67 49.56 48.31 41.83 39.01 21.81 norbornene Exo indanyl-8.63 12.90 16.21 19.00 21.43 23.71 norbornene Tricyclopentadiene — — — —0.14 — Benzofluorene — 0.20 2.01 3.07 6.05 5.33 Benzofluorene isomer — —— 0.08 1.66 1.85

Example 7 shows indanylnorbornenes can be prepared faster with themethod of the present invention, but the fraction of product in theproduct mixture is only 64.5% at its best. Furthermore, significantformation of adverse tricyclopentadiene cannot be detected at all.Benzofluorene begins to form at 60 minutes after the start of thereaction and an isomer of this at 100 minutes. The high temperatureseems to favour, however, the formation of exo indanonorbornene.

EXAMPLE 8

(Reference, Batch Process)

Indene and dicyclopentadiene (DCPD), the purity of which was at least90%, were weighed into a reactor in an amount corresponding to a molarratio of 64:36. 10 000 ppm of 97% 4-tert-butylcatechol was used as aninhibitor to prevent oligomerisation reactions of the startingmaterials. Oxygen was removed from the reaction mixture prior to thereaction by allowing nitrogen gas to pass through it. Thereafter, thereaction mixture was heated to 180° C. and allowed to react for 4 hours,after which it was cooled down to 30° C. The composition of the oily,dark yellowish reaction mixture is presented at various times aftercommencing the experiment in Table VIII.

TABLE VIII Composition of the oily reaction product expressed as masspercentage at various times after commencing the experiment Time/min 6080 100 130 160 190 270 Cyclopentadiene 0.06 0.03 — — — — — Indene 47.1835.64 27.43 25.38 22.98 21.72 23.74 Dicyclopentadiene 19.30 12.09 7.343.99 2.44 1.22 — Endo indanyl- 29.31 45.62 57.27 60.59 64.15 61.85 55.16norbornene Exa indanyl- 4.14 6.61 7.64 9.53 8.70 12.13 14.70 norborneneTricyclopentadiene — 0.01 0.17 0.17 0.36 0.32 0.39 Benzofluorene — —0.15 0.34 1.37 2.75 5.62 Benzofluorene isomer — — — — — — 0.40

Example 8 shows that with this method the fraction of indanylnorbornenein the reaction mixture is 74.0% at its best at 190 minutes after thestart of the experiment, but the formation of adverse tricyclopentadieneoccurs in varying amounts already at 80 minutes. The formation ofbenzofluorene begins at 100 minutes after the start of the experimentand an isomer of this at 270 minutes.

The terms and expressions which have been employed are used as terms ofdescription and not of limitation, and there is no intention in the useof such terms and expressions of excluding any equivalent of thefeatures shown and described or portions thereof, it being recognizedthat various modifications are possible within the scope of theinvention.

What is claimed is:
 1. A method of producing a substituted derivative ofnorbornene by the Diels-Alder reaction, the method comprising: reactinga cyclic diene selected from the group consisting of dicyclopentadieneand cyclopentadiene with an olefin compound selected from the groupconsisting of styrene and indene to yield the substituted norbornenederivative wherein the cyclic diene is added gradually during thereaction, the substituted derivative being phenyl norbornene orindanylnorbornene.
 2. The method of claim 1 wherein the cyclic diene isdicyclopentadiene.
 3. The method of claim 1 wherein the olefin compoundis styrene.
 4. The method claim 1 wherein the olefin compound is indene.5. The method of claim 1 wherein the reaction is carried out as acontinuous process or a semi-batch process, during which at least afraction of the cyclic diene to be used is added subsequently to thestart of the reaction.
 6. The method of claim 1 wherein the molar ratioof the olefin compound and the cyclic diene at the beginning of thereaction is 51:49 to 99:1.
 7. The method of claim 5 wherein the reactionis conducted at a temperature which is varied during the reaction. 8.The method of claim 7 wherein the ratio or the reagents and/or thetemperature are controlled as a function of time in a batch orsemi-batch method.
 9. The method of claim 1 wherein the reactiontemperature is 150-300° C.
 10. The method of claim 7 wherein the ratioof the reagents and/or the reaction temperature are controlled in such away that the yield and purity of the substituted norbornene derivativeare as high as possible or the yield of the exo diastereomer of thesubstituted norbornene derivative or yield of tetracyclododecene is ashigh as possible.
 11. The method of claim 1 wherein the cyclic diene iscyclopentadiene and said cyclic diene is obtained from dicyclopentadieneby cracking immediately prior to contacting the cycle diene with theolefin compound.
 12. The method of claim 1 wherein the reaction isconducted in a reactor system and the ratio of the reagents andtemperature are controlled at various points within the reactor system,said reactor system being optionally an operating autoclave, a tube, aloop or a cascade consisting of said reactors.
 13. The method of claim12 wherein the olefin compound is used as a reaction medium.
 14. Themethod of claim 12 wherein the olefin compound, an inhibitor or achemical reagent is added as a function of time or to various points ofthe reactor system.
 15. The method of claim 12 wherein a solvent, theolefin compound or any other undesired product component is recycled andoptionally cracked.
 16. The method of claim 6 wherein the molar ratio is55:45-90:10.
 17. The method of claim 16 wherein the molar ratio is80:20-60:40.
 18. The method of claim 9 wherein the reaction temperatureis 160 to 250° C.
 19. The method of claim 18 wherein the reactiontemperature is 170 to 220° C.